So I was replacing my top idler pulley since it still gave a bit a chirp. I started to tighten the bolt when all of the sudden there was a crack and the tension on the bolt just let go.. (got myself a good gash on my middle finger against the P/S pulley too)

So heres the hole the bolt is supposed to attach to..

And when I got the bolt out, I found this happened...

I tried putting the bolt back in but it only tightens so far before becoming loose again..
What's the fix for this???

In the future, that bracket as well as several other component brackets under the hood are made of aluminum, and you never tighting down a bolt in an aluminum socket with a bar...Ive always been told by the greats that you tighten it down as much as you can with your fingers and take a wrench and put it a quarter turn past that...anything more and what happened to you happens.

What you can do is drill and tap it and use a larger bolt, essentially what a helicoil is, is a kind of "replacement" thread for the hole you striped out. But you can also just go to your auto parts store and usually rent a tap and die set and just drill your own threads into the striped hole and like I said, use a larger bolt other than your stock one

Is that not a helicoil that was pulled out? Looks like it was repaired before.

If you can access the rear of the hole (which it looks like you can), just get a longer bolt and use a nut on the other side of the bracket.

It looks like a Heli-Coil, but is not.

A Heli-Coil is wound from diamond-shaped stainless steel wire. Note that the outside of the "coil" that was pulled out is relatively flat - what happened is that the threads were sheared out of the aluminum casting, and pulled with the screw. I've seen this before, and it always looks just like the pictures.

To install a Heli-Coil (or similar Screw Thread Insert,) you'll get a kit with the inserts, a drill bit, tap, and an installation mandrel. Keep these items together! (NB: You can always buy replacement inserts easily. The drill bit is typically a standard size, but not always. The taps are difficult to find.) Drill in nice and straight, then tap (the tap will follow the hole. This is why drilling the hole straight is important.) The coil is wound onto the installation mandrel, then screwed into the hole. Screw the coil down about one thread past flush with the surface, then reach down the hole (long-nose pliers) and snap out the tang at the bottom.

A Heli-Coil is typically considered a "permanent" repair, and I've used them in a variety of locations (including cylinder head screw holes!) with sound results.

A Heli-Coil is wound from diamond-shaped stainless steel wire. Note that the outside of the "coil" that was pulled out is relatively flat - what happened is that the threads were sheared out of the aluminum casting, and pulled with the screw. I've seen this before, and it always looks just like the pictures.

To install a Heli-Coil (or similar Screw Thread Insert,) you'll get a kit with the inserts, a drill bit, tap, and an installation mandrel. Keep these items together! (NB: You can always buy replacement inserts easily. The drill bit is typically a standard size, but not always. The taps are difficult to find.) Drill in nice and straight, then tap (the tap will follow the hole. This is why drilling the hole straight is important.) The coil is wound onto the installation mandrel, then screwed into the hole. Screw the coil down about one thread past flush with the surface, then reach down the hole (long-nose pliers) and snap out the tang at the bottom.

A Heli-Coil is typically considered a "permanent" repair, and I've used them in a variety of locations (including cylinder head screw holes!) with sound results.

I would agree.. But I still see thread in that hole.. It looks like a previous repair to me.. But who knows.

I would drill thru the bracket and use a longer bolt.. I personally wouldnt rely on the helicoil to hold it..